Means for obtaining flame effects in negative glow devices



Nov. 12, 1935. A. F. HENNINGER. J 2,020,413

MEANS FOR OBVTAINING FLAME EFFECTS IN NEGATIVE GLOW DEVICES i Filed May18, 1951 RQ-@UQ nnpaanauannnngnuunnnu unnnngppananppnpppg'.

Patented Nov. 12, 1935 UNITED sTATEs I MEANS FOR OBTAINING FLAME EFFECTSI 1N NEGATIVE GLOW DEVICES Andrew F. Henninger, Jr., Chicago, Ill.

Application May 18, 1931, Serial No. 538.052

' realms. -(ci. 11s-'14) This invention relates to negative glowdevicesI and has for its principal purpose the provision of a negative glowdevice wherein a ilaming effect in, conjunction with the figure designor legend may be obtained.

My invention'also-contemplates the provision of novel means forcontrolling the discharge between electrodes in a negative glowdevicewhereby to create a visible flaming appearance between theelectrodes. y

My invention contemplates further the provision of a novel combinationembodying a flaming discharge between electrodes and a flashing de.-sign. With this combination, it is possible to obtain some very strikingand attractive effects which may be used for display purposes.

I will describe the preferred formof my 'invention by reference to theaccompanying drawing Whereinl Fig. 1 is a side view partly in section ofthe negative glow device embodving my invention that, by using certaincombinations of elements in a gas filled envelope, for example, one conutaining neon or other gas such as argon, krypton, helium, zenon, ormercury vapor, I can produce a flaming discharge which when properlyapplied greatly enhances the striking eect produced by the negative glowin conjunction with an electrode having-a particular design embodiedtherein. I find that to obtain the best results, "it is necessary to usea practically pure gas because, if impure gases are used, theamingefiect is reduced; if the impurities are too great, it iseliminated completely. I also find that, while a slight amount ofimpurities or other gas in the gas bring out the figures or designs moredistinctly, the brilliant glow due to the gas'is destroyed to a certaindegree particularly when neon gas is used as the filling.

In preparing the envelopes, I preferably use' a slightlyhigher pressurethan that I normally use in negative glow devices. With neon gas, the

normal pressure I have used is about ten to twelve millimeters ofmercury, and, for obtaining the best flaming eiect, I flnd it is betterto use a pressure of around eighteen to twenty millimeters of mercury.y,

lReferring now to Figs. 3 and 4 as embodying the simplest form of theinvention, I have two electrodes 5 and 6 which, ii placed in a neon gas5 Fig. 4. This barrier is preferably entirely dis- 15 connected from theexterior of the tube so far as any conductive connection is concerned.The shield may be made of metal which I havefound to be verysatisfactory or it may be made of some other suitable substance.initiated with the shield` 9 in place follows the shortest path betweenelectrodes 5 and 6, as for example in the direction of the arrows shownin Figs. 3 and 4, and along this path there is produced the appearanceof a flame or moving glow. 25 As to the exact cause or theory underlyingthis phenomenon, I am not suiilciently sure to state such theory;however, I nd that'I am able to reproduce this condition at will byusing a shield in the manner shown in the drawing and con- 30 forming towhat is otherwise good practice in ther art of making negative glowdevices.

This flaming effect giving thel appearance of burning designs on theelectrodes 5 and 6 per- -mits me to employ the effect in a number of 35striking ways one of which is illustrated in Figs. l and 2. In thesefigures an evacuated bulb or envelope II) has mounted therein aplurality of elements II, I2, I3, and I4. Element I2 forms the shieldand in the present instance has cut out 40 therefrom a design-indicatedby the word Radio at I5. Similarly electrode I4 has a certain design asindicated at I6 cut out from it.

The lead-in wires Il and I8 and I9's e rve also as the supporting meansfor supporting the ele- 45 ments, and the element I2 which has no leadin wire is supported by means of the insulated bushings, indicated forexample at 20 and 2I, from the elements Il and I3. f

The circuit connections are provided in Fig. 2 50 by means of whichelectrode II may always be kept in circuit while electrodes I3 and I4vare alternately caused to glow. The circuit disclosed in Fig. 2 is verysimple and, of course, may be made more involved if it is desired to usea large The discharge when 20 number of electrodes to obtain differenteffects. It consists essentially of the input transformer 2I, limitingresistance 22, a thermostat 23 having a heating coil 24 and adapted toopen and close one circuit at 2B. Electrode II isl connected as shown toone end of the transformer 2| while electrode I4 is connected to theother end of the' transformer. Electrode I3 being closer to electrode II and slightly larger than electrode I4 4will tend to take the currentwhen it is connected in parallel with electrode I4. It is, however,alternately vconnected in parallel and removed by means of thethermostat 2J and a heating coil 24. Since the details ofV this circuithave been explained fully in my previous applications,-Serial lNo.516,079 and Patent No. 1,960,245, dated May 29, 1934, it is believedthat the operation thereof to alternately cause electrodes I3 and I4 toglow will be understood without further explanation.

When two of the electrodes are glowing, I obtain a very striking effectin that the front side of electrodes I I which maybe insulated on theback side as indicated at 26 will glow and the discharge will take placefrom say electrode I 3 to electrode II and produce fiery streamerspassing through the openings ofthe design I5 in the shield I2 becausethis is the shortest path to electrode II. The eiect, therefore, i'sthat the top of electrode Il is burning, and the flames are being suckedthrough the openings in the shield I2 to the glowing background or firewhich is merely the negative glow on the surface of Velectrode II.Electrode I4 being dark at this time also shows a glow through thedesign opening I6 to produce'an added attraction. Now if the circuitischanged by the opening 'of contact 25 by thermostat 23, electrode I3will become dull or dark while electrode I4 willaglow, and the `sainefiery streamer effect from the top of I4 will conltinue to occur.Instead of having a glowing design or legend upon a dark background,there will now be present a glowing background with the dark letters.

By various combinations of this character, I-

amable to present some very striking and attractive displays.

From the above descriptiom'it is believed that the constructionandoperation of this device will be clear to those skilled in this art.It is also believed to be obvious that various minor modiilcations maybe made without departing from the scope'of the invention as set forthin the opening paragraphs of the specification and in the claims. l l

Having thus described myinventionfwhat I claim as new and desire tosecure by Letters Patent is:

1'. A negative glow device comprising an envelope having'a gaseousfilling of the inert gas group at a pressure of above fteen millimetersof mercury and having therein a pair of spaced electrodes associated toform a design, means for connecting a source of alternating currentacross said electrodes to cause negative glow on both, and a shieldinterposed in the path of discharge between said electrodes operatingupon passage of current between said electrodes to cause a naming lightbetween the electrodes in addition to the glow on the electrodes theedges of said of said electrodes.

2. A negative glow' display lamp structure for causing flaming effectsbetween electrodes of the lamp including an envelope, a gaseous fillingfor said envelope at a pressure of approximately eighteen to twentymillimeters of mercury, a pair 5 -of display forming electrodes in saidenvelope,

means for connecting a source of alternating current across saidelectrodes to cause negative glow on both, and a' shield interposedbetween v' 4. A negative glow display lamp structure for causing flamingeffects between electrodes of the 25 lamp including an envelope, agaseous filling for said envelope at a pressure of approximatelyeighteen to twenty millimeters of mercury, three display formingelectrodes in said envelope, means for selectively and successivelyconnecting 30 a source of alternating current across different pairs ofsaid electrodes whereby to cause negative glowon the pairs ofelectrodes, and a shield interposedvbetween one pair of electrodes, saidshield and one of said electrodes having open- 35 ings therein in theform of display legends.

5. A negative glow display lamp structure for causing flaming eifectsbetween electrodes of the lamp including an envelope, a neon gas filling'for said envelope at a pressure of approximately o eighteen to twentymillimeters of mercury, three display forming electrodes in saidenvelope, means for selectively and successively connecting a source ofalternating current across different pairs of said electrodes whereby tocause 4;, negative glow on the pairs of electrodes, and a shieldinterposed between one pair of the electrodes.

6. A negative glow device comprising an envelope having a. gaseousfilling of a substantially 50 pure inert gas, said gas being/under apressure of between ten to twenty millimeters of mercury,

a pair of spaced electrodes therein, means for connecting a source ofalternating current across said electrodes to cause negative glow onboth, and a shield interposed in the path of discharge between saidelectrodes, edgesvof said shield being extended beyond correspondingedges of one of said electrodes. l

7. A negative glow device comprising an en- 00 velope having a gaseousillling'of'a substantially pure inert gas,y said gas being under apressure of approximately fifteen to twenty millimeters of mercury, apair of spaced electrodes in said envelope, means for connectinga'source of alter- 65 nating current across said electrodes to causenegative glow on both, and a shield interposed in the path of dischargebetween said electrodes. said shield being of substantially greater areathan'one of said electrodes. .70

ANDREW F. HENNINGER. Jn.

